A Gantt chart is a type of bar chart, developed by Henry Gantt, that illustrates a project schedule or other data with gantt bars signifying the length of duration for each item.
The EPM Live Grid/Gantt Web Part can be added to any List App, in order to show a Gantt chart for the List App data.
Here are some example Gantt charts.
Example Task Center Gantt Chart
Example Project Center Gantt Chart